MIDI CTL Messages for T-Rex Replica

Trying to set up my old T-Rex Replica Delay with my MC6 Pro and the only info from T-Rex is the following

TAP/TEMPO (CTL. No. 20), ON/OFF(Bypass) (CTL No. 21)

Tried setting up CC Messages 20 and 21 on Channel 1 and other channels but no response. Am I missing something on the type of command the pedal wants to see?

What CC values are you using?